Hydro/CTD Winches

The vessel is outfitted with two winches which serve both hydrographic and E/M
applications.

Winch
particulars

Model:

Markey DESH-5

Markey COM-15

Power:

Electric, 480V, 60 HP

Electric, 15 HP

Rated Line Pull:

10,954 lbs. bare drum5,000 lbs. full
drum

Average Working Speed:

60-75 m/min depending on load

Wire capacity:

10,000 m of .322" E-M cable9,200 m of 1/4"
wire rope

5,000 m of .322" E-M cable

This DESH-5 winch
has interchangeable drums that allow changing of cable type without a spooling
operation. Drum changes take several hours using the ship’s crane. Except in
emergency situations this task is done in port.

Both 1/4” hydrowire and
.322” conducting cables are currently available for use on the Markey DESH-5
winch.

The winches are located on the 01 Deck. An extendable
hydrographic boom mounted at the 02 Deck level amidships serves as the
overboarding point. The boom is sited so that instruments can be launched over
the starboard side at the point of least vessel motion, with protection from
wind and boarding seas, and with direct access to the Wet Laboratory.
Instruments can be launched through a gate in the bulwark rail, but are usually
lifted over the bulwark. The winches (and hydro boom) are operated by a crew
member from a station on the 01 Deck with a clear view of the winch, the main
deck work area and over the side.

The cable is led directly from the
winch to a fairlead sheave mounted at the base of the boom and then directly to
the head block mounted at the end of the boom. Both sheaves have a tread
diameter of 19”. In service the cable plumbs to a point 6-7 feet outboard of the
rail. When fully retracted, the boom plumbs the cable 4 feet inboard of the rail
and 8 feet aft of the Wet Lab doors. The head block has an unobstructed vertical
clearance to the Main Deck of 19.5 feet.

Sensors for the cable
monitoring system are mounted in the fairlead sheave. Cable parameters of line
count, line speed and tension are monitored by a Metrox digital system and
displayed in the Main Laboratory, at the winch control station and on the
bridge. Voice “squawk box” communication between laboratories, winch and the
bridge is provided with hand sets or head sets.

The winches are capable
of computer-controlled operation which allows automation via input signals from
scientific sensors. Persons desiring this feature should contact the Marine
Operations Coordinator well in advance of the cruise to assure proper
interfacing.

This winch is
designed to handle UNOLS standard 9/16”, 3x19 trawl wire rope and the WHOI-owned
.68” fiber optical tow cable. Currently two storage drums are in the WHOI
inventory. Cable storage drums are interchangeable allowing the change of cable
type without the need for a spooling operation. Drum changes take several hours
using the ship's crane and are done only in port.

The traction winch
system is composed of five basic components: the traction head pulling unit, the
level-wind/guide device, the storage drum assembly, the electrical
controller/hydraulic pump unit and the fairlead sheave assembly. All units
except the fairlead sheave are located below decks. The storage drum is located
under a deck hatch to facilitate drum changes. All instruments and attachments
must be removed from the wire prior to passing through the sheave
train.

In operation, the cable/wire is led from the storage drum (where
it is stowed under low tension) to the level-wind/guide located immediately
adjacent to the drum. It is then led directly to the traction head assembly
which is the main load bearing and pulling unit. Five wraps are taken on the
dual-headed traction unit to transition from the low storage tension to the high
working load. The cable is then led directly up to the fairlead sheave located
on the 01 Deck aft of the ship’s crane. The fairlead sheave is a universal
flagging unit which permits the cable to be led to any point on the weather
deck. Typically the cable is led directly aft to the ship’s stern “A” frame. The
ship’s crane may also be used as an overboarding support point; this requires an
additional boom crutch, available on request.

Sensors for the cable
monitoring system are mounted in the fairlead sheave. Cable parameters line
count, line speed and tension are monitored by a dedicated digital system and
displayed in the Main Laboratory, at the winch control station and on the
bridge. Voice “squawk box” communication between laboratories, winch control and
the bridge is provided. A closed-circuit TV system monitors the winch with
displays at the control station and on the bridge.

The winch is operated
by a crew member and can be controlled from two stations. When the instrument is
deployed and clear of the ship, control is switched to a station located in the
after end of the Main Laboratory adjacent to depth recorders and other
scientific display units and with a clear view of the main deck work area. This
allows the winch operator to be physically integrated into the team running the
station. The winch can also be controlled locally in the winch room.

Oceanographic Cables

Four standard categories of oceanographic cables (trawl, electro-mechanical/CTD,
hydrographic and coaxial) can be made available on board WHOI vessels. The
significant characteristics of each wire are given in the following
table.

Trawl

Hydro

E-M/CTD

Fiber Optic

Size

9/16"

1/4"

.322"

.681"

Length

9,152 m

9,152 m

10,000 m

6,000 m

Construction

3 x 19 galv.

3 x 19 galv.

2 armor galv.

3 armor galv.

Manufacturer

Macwhyte

Macwhyte

Rochester

Rochester

Manuf. ID

9/16" AA

1/4" AA

01592

02351

R.B.S.

32,500 lbs.

6,750 lbs.

11,600 lbs.

46,000 lbs.

Yield

24,375 lbs.

5,063 lbs.

5,000 lbs.

---

2% Yield

28,600 lbs.

5,900 lbs.

---

---

S.W.L.

14,300 lbs.

2,950 lbs.

4,500 lbs.

14,000 lbs.

Wet Wt.

1,370 lbs./km

284 lbs./km

462 lbs./km

2,006 lbs./km

Dry Wt.

1,614 lbs./km

327 lbs./km

571 lbs./km

2,465 lbs./km

Min. Sheave Dia.

21"

12"

12"

48"

DC Resistance @ 20 deg

---

---

3 cond., 9.4 ohm/1,000'

---

Backup or spare
reels exist for each type of oceanographic cable through the UNOLS cable pool
system. In general, because of weight and space limitations spare cables are not
carried aboard Oceanus. On extended voyages, a backup reel for the most
critical oceanographic cable can be carried aboard if requested and available.

All oceanographic cables aboard WHOI vessels are lubricated during
manufacture with Grignard Chemical Co. Pre-Lube #6 or #19. Cables are
periodically rinsed and lubricated with the same product during service. Cable
lubrication may be deferred if there is concern about potential contamination of
sampling.

It is imperative that oceanographic cables be used in a
responsible manner which does not compromise their availability to subsequent
investigators. Cables are expensive and at times in short supply. Reasonable
care must be taken to maintain their integrity and extend their useful life.
Questions related to the use of cables should be directed to the Marine
Operations Coordinator during cruise planning.

Notes, cautions, and
restrictions to the use of cables:
1. Cables are not to be loaded in excess of their safe working load.
Caution must be exercised in lowering instruments which are heavy, entrap large
volumes of water, or produce excessive hydrodynamic drag forces. This is
particularly true when operating in moderate sea states or water depths greater
than 4,000 meters.

2. Cables will not be permitted to pass over sheaves which are not properly
sized (groove size and tread diameter) for that cable.

3. In general, devices are not to be clamped onto any conducting cable. This
is to prevent damage to conductors and their insulation. The exception is that
devices may be clamped within 100 meters of the termination.

4. Certain operations, such as dragging for moorings, deliberately subject
cables to severe abuses such as kinking and abrasion. Whenever possible, the
main cables will be protected from abuse by splicing or attaching sacrificial
wires of comparable strength to the end.

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